1. Field of the Invention
This application is directed to a fluidic gas angular rate sensor and more particularly to a phase locked driving circuit for a piezoelectric pump in a fluidic gas angular rate sensor.
2. Description of the Prior Art
In prior art fluidic gas angular rate sensors, such as those shown in U.S. Pat. Nos. 3,500,691, 4,020,699 and 4,020,700, the angular movement of a body is detected by measuring a temperature differential between two temperature sensors. Typically, a gas flow is produced by means of a piezoelectric pump and the gas flow is directed towards two temperature sensing elements in a closed jet chamber. The flow of gas is such that the flow is directed equally at the two temperature sensors thereby maintaining the temperature of each sensor equal. When the body on which the sensor is mounted undergoes an angular displacement, the flow of gas is deflected and thus the flow striking each of the temperature sensors becomes unequal resulting in a temperature differential between the two temperature sensors. This temperature differential is indicative of the angular displacement of the body.
One of the problems in prior art fluidic gas angular rate sensors is inaccuracies which are introduced by variations in gas flow caused by instability in the operation of the piezoelectric pump.